Primjena umjetne toplinske stimulacije kao novi pristup za indukciju tendinopatije u magaraca

Animal models for tendonitis are essential for studying the disease’s mechanism and pathogenesis, and evaluating different therapeutic protocols. The temperature seems to play a significant role in tendinitis initiation. The aim of this study was the generation of a novel, safe and cheap tendinitis model, and validation of its reliability. The effect of microwave diathermy (30 watts for 30 min) on the flexor tendons of donkeys as animal models was investigated after 15, 30 and 60 days. The evaluation was based on geometric analysis, ultrasonography, histomorphometric analysis and scanning electron microscopy (SEM). Microwave diathermy was capable of successfully inducing well-defined lesions in the superficial digital flexor tendon (SDFT) as well as the deep digital flexor tendon (DDFT). The results showed that all the animals exhibited signs of lameness, starting on day 15 and reaching on maximum on day 30. A significant increase in limb circumference was also detected on day 30 (P<0.05). Furthermore, the geometrical analysis of the proportion of induced lesion (PIL) in correlation with the tendon diameter, revealed that PIL was at the maximum width on day 30 (20.6 ± 1.2% for SDFT and 15.7 ± 0.7% for DDFT), as detected by ultrasound. Moreover, a high number of rounded tenocytes, bleeding, severe matrix disruption, and an increase in fiber thickness were detected by histomorphometric analysis. Also, the matrix alignment was severely disrupted in both SDFT and DDFT by day 30, as confirmed by SEM. In conclusion, using microwave diathermy for induction of tendonitis in donkey is a reliable, minimally invasive, and cost-effective tendonitis model.Uporaba životinjskih modela je neophodna za proučavanje mehanizma bolesti, patogeneze i za procjenu protokola liječenje tendinitisa. Čini se da temperatura igra značajnu ulogu pri nastajanju tendinitisa. Cilj istraživanja bio je stvaranje novog, sigurnog i jeftinog modela za proučavanje tendinitisa te potvrda njegove pouzdanosti. Učinak mikrovalne dijatermije (30 vata tijekom 30 min) na tetive fleksora u magaraca kao životinjskih modela istraživan je nakon 15, 30 i 60 dana. Procjena se temeljila na geometrijskoj analizi, ultrazvuku, histomorfometrijskoj analizi i skenirajućoj elektronskoj mikroskopiji (SEM). Mikrovalna dijatermija uspješno je inducirala dobro definirane lezije u površinskoj digitalnoj tetivi fleksora (SDFT) kao i dubokoj digitalnoj tetivi fleksora (DDFT). Rezultati su pokazali da su sve životinje pokazivale znakove hromosti, počevši od 15. dana i dostižući maksimum 30. dana. Također, 30. dana je uočeno znakovito (P<0,05) povećanje opsega ekstremiteta. Nadalje, uporabom ultrazvuka i primjenom geometrijske analize udjela inducirane lezije (PIL) u korelaciji s promjerom tetive, ustanovljeno je da je PIL bio maksimalne širine 30. dana (20,6 ± 1,2% za SFT i 15,7 ± 0,7% za DDFT). Osim toga, histomorfometrijskom analizom otkriven je povećan broj zaobljenih tenocita, krvarenje, teži poremećaji u matriksu i povećanje debljine vlakana. Do 30. dana, SEM analiza je pokazala izražene poremećaje u poravnavanju matriksa i u SDFT i u DDFT. Zaključno, primjena mikrovalne dijatermije za indukciju tendinitisa kod magaraca je pouzdan, minimalno invazivan i troškovno učinkovit životinjski model za proučavanje ove bolesti

Telomerase reverse transcriptase coordinates with the epithelial-to-mesenchymal transition through a feedback loop to define properties of breast cancer stem cells

Telomerase and its core component, telomerase reverse transcriptase (hTERT), are critical for stem cell compartment integrity. Normal adult stem cells have the longest telomeres in a given tissue, a property mediated by high hTERT expression and high telomerase enzymatic activity. In contrast, cancer stem cells (CSCs) have short telomeres despite high expression of hTERT, indicating that the role of hTERT in CSCs is not limited to telomere elongation and/or maintenance. The function of hTERT in CSCs remains poorly understood. Here, we knocked down hTERT expression in CSCs and observed a morphological shift to a more epithelial phenotype, suggesting a role for hTERT in the epithelial-to-mesenchymal transition (EMT) of CSCs. Therefore, in this study, we systematically explored the relationship between hTERT and EMT and identified a reciprocal, bi-directional feedback loop between hTERT and EMT in CSCs. We found that hTERT expression is mutually exclusive to the mesenchymal phenotype and that, reciprocally, loss of the mesenchymal phenotype represses hTERT expression. We also showed that hTERT plays a critical role in the expression of key CSC markers and nuclear β-catenin localization, increases the percentage of cells with side-population properties, and upregulates the CD133 expression. hTERT also promotes chemoresistance properties, tumorsphere formation and other important functional CSC properties. Subsequently, hTERT knockdown leads to the loss of the above advantages, indicating a loss of CSC properties. Our findings suggest that targeting hTERT might improve CSCs elimination by transitioning them from the aggressive mesenchymal state to a more steady epithelial state, thereby preventing cancer progression

Human-induced neural and mesenchymal stem cell therapy combined with a curcumin nanoconjugate as a spinal cord injury treatment

Altres ajuts: Fundació Marató TV3 2017/refs.20172230, 20172231 i 20172110We currently lack effective treatments for the devastating loss of neural function associated with spinal cord injury (SCI). In this study, we evaluated a combination therapy comprising human neural stem cells derived from induced pluripotent stem cells (iPSC-NSC), human mesen-chymal stem cells (MSC), and a pH-responsive polyacetal-curcumin nanoconjugate (PA-C) that al-lows the sustained release of curcumin. In vitro analysis demonstrated that PA-C treatment pro-tected iPSC-NSC from oxidative damage in vitro, while MSC co-culture prevented lipopolysaccha-ride-induced activation of nuclear factor-κB (NF-κB) in iPSC-NSC. Then, we evaluated the combination of PA-C delivery into the intrathecal space in a rat model of contusive SCI with stem cell transplantation. While we failed to observe significant improvements in locomotor function (BBB scale) in treated animals, histological analysis revealed that PA-C-treated or PA-C and iPSC-NSC + MSC-treated animals displayed significantly smaller scars, while PA-C and iPSC-NSC + MSC treatment induced the preservation of β-III Tubulin-positive axons. iPSC-NSC + MSC transplantation fostered the preservation of motoneurons and myelinated tracts, while PA-C treatment polarized microglia into an anti-inflammatory phenotype. Overall, the combination of stem cell transplantation and PA-C treatment confers higher neuroprotective effects compared to individual treatments

Diabetic microenvironment deteriorates the regenerative capacities of adipose mesenchymal stromal cells

Abstract Background Type 2 diabetes is an endocrine disorder characterized by compromised insulin sensitivity that eventually leads to overt disease. Adipose stem cells (ASCs) showed promising potency in improving type 2 diabetes and its complications through their immunomodulatory and differentiation capabilities. However, the hyperglycaemia of the diabetic microenvironment may exert a detrimental effect on the functionality of ASCs. Herein, we investigate ASC homeostasis and regenerative potential in the diabetic milieu. Methods We conducted data collection and functional enrichment analysis to investigate the differential gene expression profile of MSCs in the diabetic microenvironment. Next, ASCs were cultured in a medium containing diabetic serum (DS) or normal non-diabetic serum (NS) for six days and one-month periods. Proteomic analysis was carried out, and ASCs were then evaluated for apoptosis, changes in the expression of surface markers and DNA repair genes, intracellular oxidative stress, and differentiation capacity. The crosstalk between the ASCs and the diabetic microenvironment was determined by the expression of pro and anti-inflammatory cytokines and cytokine receptors. Results The enrichment of MSCs differentially expressed genes in diabetes points to an alteration in oxidative stress regulating pathways in MSCs. Next, proteomic analysis of ASCs in DS revealed differentially expressed proteins that are related to enhanced cellular apoptosis, DNA damage and oxidative stress, altered immunomodulatory and differentiation potential. Our experiments confirmed these data and showed that ASCs cultured in DS suffered apoptosis, intracellular oxidative stress, and defective DNA repair. Under diabetic conditions, ASCs also showed compromised osteogenic, adipogenic, and angiogenic differentiation capacities. Both pro- and anti-inflammatory cytokine expression were significantly altered by culture of ASCs in DS denoting defective immunomodulatory potential. Interestingly, ASCs showed induction of antioxidative stress genes and proteins such as SIRT1, TERF1, Clusterin and PKM2. Conclusion We propose that this deterioration in the regenerative function of ASCs is partially mediated by the induced oxidative stress and the diabetic inflammatory milieu. The induction of antioxidative stress factors in ASCs may indicate an adaptation mechanism to the increased oxidative stress in the diabetic microenvironment